Performance problems with Corelab OraDirect.Net on LOBs using Direct mode and NonDirect mode

sumit · Post by **sumit** » Fri 12 Jan 2007 02:43

Hi,

We are trying to tune our application's performance on Oracle 10g (as well as 9i) database that is currently using CoreLab 3.55.16 drivers to connect to the database in Direct mode. A lot of people are complaining about the application's performance.

I ran a comparison with System.Data.OracleClient drivers in .Net and found huge performance problems while working with LOBs.

Using Corelab Direct mode, it takes about 1.7 sec to query the database and fill a dataset from a datareader.

Using Corelab NonDirect mode, with Oracle client, it takes about 700 milli sec to do the same thing.

Using System.Data.OracleClient classes with Oracle client, it took only 250 milli secs to the same thing!!

Please let me know how to fix this issue so that we can continue to use Corelab drivers for our product.

Thanks,
Sumit

sumit · Post by **sumit** » Fri 12 Jan 2007 02:49

As a note on the data used for testing, only 30 rows were used to fill the datatable from the datareader and there are 2 CLOB columns (with data no more than 50 characters long for each row) in the table used for comparison.

Thanks.

Alexey · Post by **Alexey** » Fri 12 Jan 2007 07:37

This is known problem with performance of LOBs processing.

sumit · Post by **sumit** » Fri 12 Jan 2007 16:37

Is CoreLab planning a fix for this? If yes, how long it might take?

Thanks.

Alexey · Post by **Alexey** » Mon 15 Jan 2007 08:06

The problem is very complicated, and finding a solution may take a lot of time.

sumit · Post by **sumit** » Tue 23 Jan 2007 02:23

Hi Alexsey,

Is there a reason why the performance of a .Net 2.0 application on Oracle db using Direct mode will vary on different machines on the same network connected to same remote db under similar load conditions?

We are seeing some variations in the level of performance on various machines. For example, using NonDirect mode with Oracle 10g Instant Client runs faster than Direct mode on one machine but runs slower than Direct mode on a different machine.

What is the default data packet size that OraDirect.Net drivers uses on TCP/IP network?

Thanks,
Sumit

Alexey · Post by **Alexey** » Thu 25 Jan 2007 11:08

Could you provide me with your testing project?

sumit · Post by **sumit** » Thu 25 Jan 2007 19:00

Hi Alexsey,

I will get back to you with a sample in few days.

-Sumit

Alexey · Post by **Alexey** » Tue 30 Jan 2007 10:54

I will be looking forward.